Drying of gases



Aug. 25, 1931. QCQQPER 1,820,121

DRYING OE GASES v Filed June 6, 1927 2 Sheets-Sheet 1 C- Cooper I Aug. 25, 1931. c. COOPER DRYING OF GASES- Filed June 6, 1927 2 Sheets-Sheet 2 Patented Aug. 25', 1931 UNITED STATES PATENT OFFICE CHARLES COOPER, OF HUDDERSFIELD, ENGLAND, ASSIGNOR TO W. C. HOLMES AND I COMPANY, LIMITED, OF HUDDERSFIELD, ENGLAND DRYING F GASES Application filed June 6, 1927, Serial No. 196,970, and in Great Britain October 21, 1926.

groscopic or water-absorbing bodies u'sed being preferably treated continuously or periodically for the purpose of expelling therefrom water taken up from the gases and to restore it into the condition in which it may be conveniently used for the like purpose.

Certain proposals for effecting the removal of moisture from a1r in this way have 1nvolved a considerable reduction of the temperature of the air while according to the heatis developed and the temperature within the apparatus employed rises with the result that final contact of the gas with the hygroscopic or water-absorbing bodies in the liquid state is effected at a somewhat higher temperature than the initial contact, that is to say, the contact of the gas with the liquid at the point where the gas enters the apparatus employed for carrying out the treatment.

The object of the present invention is to provide an improved process for the drying of fuel gasesby bringlng the same into intimate contact with hygroscopic or Water-absorb ing material in the liquid state with periodic or continuous regeneration or reconcentration of the water-absorbing material.

The process in accordance, with the invention is' characterized in this that the circulation of the hygroscopic or water-absorbing material in the liquid state for securing dissipation of the heat developed as the result of removal of moisture from the gases is independent of the circulation of the hygroscope or water-absorbing material for the purpose of securing its regeneration.

. Normally the operation will be carried out in such manner as to avoid reducing the temperature of the gases materially below the temperature of the atmosphere or dissipating more heat than that set free by the mechanism of the process of moisture removal.

lVhen employing an apparatus of the type of the so-called brush washer a section of the washing space of the washer, for example the last one-third, may be associated with cooling means, being, for example, provided with an outlet for the liquid or water-absorbmg body associated with a pump adapted to continuously withdraw the water-absorbing body from this section of the apparatus, deliver it to cooling means and return it to the said section of the apparatus.

The means for circulating this proportion of the hygroscopic or water-absorbing material in the liquid state will be independent of the means adapted to secure the continuous or periodic removal of the same for the purpose of regeneration, the withdrawal of the hygroscopic or water-absorbing material for that purpose being, for instance, effected at a point adjacent to where the gas is admitted to the apparatus.

Where apparatus in the form of a tower scrubber is'provided theupper portion of the tower may be similarly arranged to secure a cooling action.

While the cooling operation is conveniently carried out in a section of a single washing apparatus it will be understood that in some cases it may be desirable to effect the removal of the greater proportion of water in one apparatus which is not provided with cooling means and then to treat the gases in a further apparatus where it is again brought into contact with hygroscopic or water-absorbing bodies in a liquid state, which apparatus is associated with cooling means.

The invention will be further described with reference to the accompanying drawings in which:

Figure 1 is an elevation partly in section ofan apparatus in which a brush washer is used for bringing into intimate contact the gas to be dried and the water-absorbingor hygroscopic body in a liquid state, the cooling means being omitted.

Figure 2 is a plan view thereof showing the cooling means and its connections.

In the drawings, 1 is the inlet to the pipe 2 provided with branches 3 in which, and in aforesaid pipe, valves 4 are provided by the appropriate adjustment of which gas may be permitted to pass direct through the pipe or in series through two washers of known character connected together by thepipe 5. These washers each comprise a casing 6 forming the washin chamber divided by partitions 7 into a pl urality of sections in each of which, secured to a shaft 8, are located discs 9 to which a plurality of brush elements 10 are connected. Each of the sections of the brush washers is provided with outlets 11 for the waterabsorbing or hygroscopic body in the liquid state employed.

These outlets are connected (see Figure 2) with pipes 12a, 12b, 12c and 1201 leading to pumps 13a, 136, 130 and 13d, the two former being arranged to be operated by an electric motor 14a, while the two latter are arranged to be operated by an electric motor 146.

The outlet 15 of the pump 13a'is arranged to deliver liquor through one of the two sections into which the heats interchanger 16 is divided, this heat interchanger being of any suitable construction and cooled by water. The liquor cooled in this section of the heat interchanger is delivered by way of the pipe 17 to the section of the washer 6 located immediately adjacent and to the right of the section from which the liquor was withdrawn and into which it will overflow. The pump 13?) withdraws liquor from the next succeeding section of the washer 6 and delivers it by way of the pipe 18 to one of the two sections into which the heat interchanger 19 is divided and from the said section of this heat interchanger the liquor is returned by Way of the pipe 20, entering the fourth section of the washer 6 and overflowing therefrom into the third section thereof, that is to say the section immediately to the left of the section to which it is so returned.

From the first section of the washer So, that is to say from the section of thesaid washer which is located on the extreme left-hand side of the washer, liquor is withdrawn through the pipe 120 by the pump 13c and delivered to a section of the cooler 19 from which it is returned by way of the pipe 21 to the second section of the said washer from which in turn it overflows into the first section. -Liquor is withdrawn from the third section of the said washer by way of the pipe 12d andby the pump 13d and is delivered by way of the pipe 22 to a section of the heat interchanger 16 from which it passes by way of the pipe 23 to the fourth section of the washer overflowing into the third section thereof.

It is necessary that the liquor thus maintained in circulation shall be continuously or periodically concentrated or, in other words, treated to expel from-the liquor the water which is taken up from the gas. To this end it is arranged to be withdrawn from the washer 6 by a pipe 24, being delivered to the weak liquor tank 25 from which it ma be withdrawn at a regulated rate by way 0 the pipe 26 through the intermediary of the pump 27, a portion being delivered by way of the pipes 28 and 29 to the tank 30 while a further portion is delivered by way of the pipes 28-31 to the evaporator 32, the liquor passed over the evaporator returning by way of the pipe 33 to the tank 25.

By suitably regulating the relative propor tions of liquor delivered respectively directly to the tank 30 and over the evaporator the concentration of the liquor supplied from the tank 30 by way of the pipe 34, the funnel 35 and pipes 36 and 37 to the washer may be adjusted to secure the desired degree of moisture removal from the gas.

Alternatively, the pump 27 may be operated at intervals only, that is to say after a certain amount of liquor has accumulated in the tank 25 so as to deliver the whole of the liquor contained in this tank over the evaporator in order to secure its concentration to a suitable degree after which the concentrated liquor may be transferred from the tank 25 and delivered into the tank 30. This latter method of operation is perha s less suitable where onl small quantities o steam or other heating uid are available.

As will be understood, the above descri tion is furnished for the purpose of descri ing the nature of the invention and where apparatus or methods have been described in some detail the scope of the invention is not necessarily to be regarded as limited by such detailed description.

Having now described my invention what I claim as new and desire to secure by Letters Patent is The process of drying fuel ases which comprises causing the gases to ow in intimate contact with a main body of hygroscopic material in the liquid state, continuously Withdrawing a portion of the said main body of hygroscopic material, cooling the same, returning the cooled liquid to the main body of materlal and continuously and separately withdrawing a further portion of the main body of hygroscopic material, subjecting the same to treatment to expel a portion of its content of water and continuously returning the liquid after such treatment to the main body of hygroscopic material.

In testimony whereof I have signed my name to this specification.

CHARLES COOPER. 

